Beverage producing systems using disposable beverage cartridges of capsules are commonly used for preparing coffee-based beverages or other edible products. A capsule is usually introduced into a brewing chamber, pierced on the top and on the bottom and the beverage is extracted by flowing hot and pressurised water through the capsule. Depending upon the kind of the capsules used, the water pressure and/or temperature or the flow rate, as well as upon the ingredients contained in the capsule, beverages of different quality and nature can be obtained.
Brewing espresso coffee requires flowing hot and pressurized water through the capsule containing coffee powder. Water is usually fed into the capsule at reduced flow rate and at around 12/15 bars. Such a high pressure value is required to form the cream on top of the espresso coffee.
So-called fresh-brew coffee or “American coffee” is usually produced by flowing a large amount of water at reduced or zero pressure across a coffee powder bed.
Usually coffee producing devices are designed to produce either espresso coffee or so called American coffee or fresh brew coffee. Attempts have been made to provide devices capable of forming different kinds of coffee-based beverages. There is however still a need for a system which is capable of producing beverages having variable organoleptic characteristics using the same single-serving package, for example a capsule or cartridge.
US-A-2011/0111098 discloses a brewing system including a capsule having a bottom wall with a groove. The groove is asymmetrically arranged with respect to the capsule and is intended for positioning the capsule in only one pre-determined angular position in a brewing chamber. The brewing chamber comprises two identical piercers arranged symmetrically with respect to the brewing chamber axis and off-axis, i.e. distanced from said axis. Each piercer is in fluid communication with a respective beverage dispensing duct, said two dispensing ducts being independent and separated from one another. The planar bottom wall portion of the capsule has an indentation in a position corresponding to one or the other of said two piercers. Thus, upon insertion of the capsule in the brewing chamber, a fluid communication will be established between the capsule interior and only one of said piercers. Two kinds of capsules can be used with the same brewing unit, differing by content and position of the indentation. Either one or the other piercer and corresponding dispensing duct will be used, depending upon the content of the capsule, so that different beverages (e.g. tea and coffee) can be produced with the same device. This prevents contamination of one beverage by the residues of the other beverage in the dispensing duct, since the dispensing ducts are independent and selectively used depending upon the shape of the capsule bottom, i.e. depending upon the position of the indentation on the bottom of the capsule.